This invention relates to food processing. More particularly, the invention relates to a method for improving the quality of meat products by manipulating the pH of the meat product.
Almost all foods are processed in some way before reaching the consumer. Meat products, for example, are separated from unusable or undesirable elements or components, ground or chopped, mixed or blended, and often times frozen for distribution. Even lightly processed meats are cut, trimmed, and then packaged for sale or distribution.
Microbes are part of the natural decay process of organic material and invariably appear or grow in foodstuffs as they are processed or handled. Although some microbes may be relatively benign, others contribute to spoilage and some can cause serious illness if consumed. Lactic acid producing bacteria are examples of benign microbes while some strains of E. Coli, Salmonella, Staph, and Listeria bacteria are examples of pathogens and can cause serious illness.
It is, therefore, desirable to control the growth of pathogen microbes or reduce pathogen microbe count in foodstuffs. Historically, microbe growth has been reduced by chemical preservatives that remain in the product and are ultimately ingested by the consumer. Chemical preservatives, however, may have undesirable side effects to consumers and, in any event, a growing population has expressed a desire for food products that are free of traditional chemical preservatives. Alternatively to traditional chemical preservatives, heat has been used to kill microbes in foodstuffs. However, heat processing or sterilization often has an undesirable effect on the quality or characteristics of the foodstuff and may make the product undesirable to the consumer. Also, heat sterilization in meats can kill all microbes, leaving the meat susceptible to the rapid growth of dangerous microbes or pathogens after sterilization, should the previously sterilized meat be exposed to pathogens.
U.S. patent document, Ser. No. 08/210,571, now U.S. Pat. No. 5,433,142, was directed to an apparatus and method for improving the quality of a foodstuff by treating the product with a pressurized gas in contact with the product. The method of treatment according to that invention included placing the gas under an operating pressure in contact with the foodstuff and holding the pressure for an operating period. After the operating period, the method continued with releasing the gas pressure, preferably instantaneously. The exposure to the pressurized operating gas and then rapid decompression killed microbes on or near the surface of the foodstuff. Although the exact mechanism by which this pressurized gas treatment operated to kill microbes is not fully understood, it is believed that the physical action of gas decompression damaged the microbe cells to kill the microbes. In any event, the invention set out in U.S. Pat. No. 5,433,142 did not modify the treated foodstuff chemically and relied upon the pressure/decompression step to physically damage microbes.